Focused ion beam irradiation for generation of skyrmionic bubble like structures

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:523

Article

Ahrens, Valentin¹  Mendisch, Simon¹  Kaiser, Waldemar²  Kiechle, Martina¹  Breitkreutz-von Gamm, Stephan³  Becherer, Markus¹ 

[1] Tech Univ Munich, Dept Elect & Comp Engn, Chair Nanoelect, Arcisstr 21, D-80333 Munich, Germany

[2] Tech Univ Munich, Dept Elect & Comp Engn, Simulat Nanosyst Energy Convers, Arcisstr 21, D-80333 Munich, Germany

[3] Infineon Technol AG, Campeon 1-15, D-85579 Neubiberg, Germany

关键词: Magnetic multilayers;    Room temperature skyrmionic bubble like structures;    Zero field skyrmionic bubble like structures;    Artificial skyrmionic bubble like structures;    Perpendicular Magnetic Anisotropy (PMA);    Ion beam irradiation;   

DOI  :  10.1016/j.jmmm.2020.167591

来源: Elsevier

【 摘 要 】

Skyrmions provide high potential for low power magnetic computing. However, we are lacking methods for the controlled nucleation of skyrmions in magnetic thin films. We present a procedure for a controlled generation of skyrmionic bubble like structures (SBSs) at well-defined spots by focused ion beam (FIB) irradiation of magnetic multilayers. Series of Pt/Co/Ir and Pt/Co/W multilayers with interfacial Dzyaloshinskii-Moriya interaction (iDMI) were sputtered and optimized with respect to the domain structure and development under magnetic field. Applying an external magnetic field pulse of specific strength to a sample in both the demagnetized domain state and the uniform ferromagnetic state results in the condensation and nucleation of bubbles, respectively. In multilayer films, SBSs form randomly across the sample. To control the bubble nucleation, we irradiate the multilayer stacks with 50 kV Ga+ ions to alter the magnetic properties along a hexagonal grid. We observe nucleation and geometric confinement of bubbles within the center of the hexagons. The lowered anisotropy in irradiated regions forms potential barriers which stabilizes the bubbles at room temperature and zero field. FIB tuned magnetic thin films give an exciting platform to investigate the behavior of SBSs in a confined state and to study the possibilities of controlled field- and current-driven motion.

【 授权许可】

Free